Penelope Wilton
From Tardis Wiki, the free Doctor Who reference
Penelope Wilton (born 3rd June 1946) played Harriet Jones in Aliens of London, World War Three, The Christmas Invasion and The Stolen Earth. She also played a reporter/Torchwood informant in "The Sound of Drums".
She starred in Shaun of the Dead with fellow Doctor Who actors, Bill Nighy and Simon Pegg.